LOTT Sludge Dewatering System Upgrade

The existing sludge dewatering system at the Budd Inlet WWTP had been in place since the 1980s. The equipment was aging, hard to access, not reliable, and becoming increasingly expensive to repair. This project was a complete replacement of LOTT’s solids processing system, encompassing design and equipment selection, completion of a temporary dewatering system, pilot testing of equipment, and construction of the new sludge dewatering system within the existing building.

The system includes two 3,500 lb/hour horizontal decanting centrifuges; new dry polymer system with progressing cavity polymer solution metering pumps; shaftless screw conveyors to transport dewatered sludge from each centrifuge to LOTT’s sludge truck loadout area; digested sludge grinders; process piping and instrumentation for integration with thickening and digestion; grinders downstream of the plant digesters; relocation and upgrade of the operator facilities and lab; substantial structural improvements to the centrifuge platform and sludge loadout and centrate handling facilities; and rework of the electrical room.

Parametrix worked alongside LOTT’s team to deliver a project that increased solids handling capacity within a very tight existing building; created improved operations facilities; reduced energy consumption; and created an integrated team project delivery process that resulted in support from operations, maintenance, engineering, electrical, and controls stakeholders. Improvements were constructed while continuously meeting LOTT’s biosolids permit requirements, without interrupting normal operations.

LOTT and Parametrix developed an integrated team approach to design and construct the improvements, helping to ensure that equipment would work seamlessly with other systems and would be easy to maintain. The project was completed approximately 3 months ahead of schedule and $300,000 below the project budget. Parametrix and LOTT developed an integrated team delivery approach, which employed laser scanning survey and 3D BIM for project plan development and delivery.

LOTT Sludge Dewatering System Upgrade


LOTT Clean Water Alliance

Olympia, WA
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